Earthquakes

Earthquake

A sudden violent shaking of the ground, typically causing great destruction, as a result of movements within the earth's crust or volcanic action it's knows as  earthquake or also known as a quake, tremor or temblor

1.0 TYPE OF EARTHQUAKE 

1. Tectonic Earthquake

The earth crust is made up of unevenly shaped slab of rocks called tectonic plates. The energy stored here causes the tectonic plates to move towards away or push against each other. With time the stored energy and the movement of the tectonic plates build up the enormous pressure within the region between two plates.

2. Volcanic earthquake

Earthquake-related to the volcanic activity are called a volcanic earthquake.

The magnitude of these quakes is usually weak.There are two types of volcanic earthquakes, which are

1.  Volcano-tectonic earthquake
2.  Long-period earthquake

2.1.0 Volcano-tectonic earthquake

The tremors happen due to injection or withdrawal of Magma between the stressed rocks is called a volcano-tectonic earthquake.

The movements of the molten magma cause mostly volcanic earthquake directly underneath a volcano.

In these types of the earthquake, magma exerts the pressure on the tectonic plates until this magma breaks the rocks.

During these cracks, tremors occur.

These earthquakes are so weak that only can be measured by sensitive instruments.

After the breakdown of rocks, magma starts flowing towards the surface of the earth.

After that, rocks have to fill up space where magma is no longer available. During filling the space, tremors happen of very low magnitude.

 2.2.0 Long-period earthquake

A long period earthquake occurs while the injection of magma into the surrounding rocks. These all happen due to the pressure changes among the layers of the earth.

These types of volcanic activity indicate the eruption of the volcano in the near future.

Seismograph records these reading, and before the actual eruption of the volcano, we can easily take preventive measures. So that local people can become aware of the eruption of the volcano.

3. Explosive earthquake

Explosive earthquake mostly happens during the testing of nuclear weapons. We know that during detonation of nuclear weapon big blast occurs and a vast amount of energy releases. Sometimes these blasts become the cause of the earthquakes.

4. Collapse earthquake

These earthquakes are of weak magnitude earthquakes happen in the caverns and mines.

Sometimes, underground blasts (Rock breaking) in the mines become the cause of the collapsing of mines and collapsing of mines produces seismic waves.

The P and S- waves (Seismic waves) produced during the explosion of rocks on or under the surface of the earth cause this type of earthquakes.

Also, Read; Top 7 Devastating and Terrible effects of a Massive Earthquake.

Conclusion

I) Tectonic and volcanic earthquakes are natural earthquakes, which we can not stop.

II) Explosive and collapse earthquakes are the man-made earthquakes, which can be 

stopped.

3.0 TYPE OF SEISMIC WAVES 

4.0 Magnitude Scale

Earthquake Magnitude Scale

Magnitude	Earthquake Effects	Estimated Number  Each Year
2.5 or less	Usually not felt, but can be recorded by seismograph.	900,000
2.5 to 5.4	Often felt, but only causes minor damage.	30,000
5.5 to 6.0	Slight damage to buildings and other structures.	500
6.1 to 6.9	May cause a lot of damage in very populated areas.	100
7.0 to 7.9	Major earthquake. Serious damage.	20
8.0 or greater	Great earthquake. Can totally destroy communities near the epicenter.	One every 5 to 10 years

Earthquake Magnitude Classes

Class	Magnitude
Great	8 or more
Major	7 - 7.9
Strong	6 - 6.9
Moderate	5 - 5.9
Light	4 - 4.9
Minor	3 -3.9

3.0 What to do during a massive earthquake?

Earthquake Preparedness: 21 steps and technique by which you can protect yourself during a giant earthquake?